Chemical Forums

Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: dulg on February 09, 2020, 11:26:25 AM

Title: Is there a way to isolate aliphatic amines from aromatic and heterocyclic amines
Post by: dulg on February 09, 2020, 11:26:25 AM

I know that the key distinction between the two (three) are their structures, and that they are classified by their structures, but I am wondering if there is a way to isolate the two using solvents. I am not an expert in this field, and would love to get some help.

I know that asking for a magic solvent to solve all of my problems is a very naive, so please forgive me for asking this.

Many Thanks,
dulg

Title: Re: Is there a way to isolate aliphatic amines from aromatic and heterocyclic amines
Post by: hollytara on February 12, 2020, 12:11:34 AM

You might be able to use acid-base properties.  Most aliphatic amines are much more basic than aromatic amines. 

So at a pH of say 8-9, the aromatic amines will not be protonated and will go into an organic solvent, the aliphatics will still be protonated and will dissolve in water

Title: Re: Is there a way to isolate aliphatic amines from aromatic and heterocyclic amines
Post by: wildfyr on February 13, 2020, 01:00:27 PM

Hollytara, thats an oversimplification... some percentage of each amine will be protonated at an intermediate pH, but the ratios will change with pH. If the pKbs are 3 units apart then perhaps you could do this with minimal crossover. I think separating a mixture this way would be pretty hard. Have you ever tried it?

Distillation strikes me as a better way to do it depending on the exact amines.